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    1 ################################################################################
    2 # WeBWorK Online Homework Delivery System
    3 # Copyright © 2000-2003 The WeBWorK Project, http://openwebwork.sf.net/
    4 # $CVSHeader$
    5 #
    6 # This program is free software; you can redistribute it and/or modify it under
    7 # the terms of either: (a) the GNU General Public License as published by the
    8 # Free Software Foundation; either version 2, or (at your option) any later
    9 # version, or (b) the "Artistic License" which comes with this package.
   10 #
   11 # This program is distributed in the hope that it will be useful, but WITHOUT
   12 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   13 # FOR A PARTICULAR PURPOSE.  See either the GNU General Public License or the
   14 # Artistic License for more details.
   15 ################################################################################
   16 
   17 package WeBWorK::DB::Driver::SQL;
   18 use base qw(WeBWorK::DB::Driver);
   19 
   20 =head1 NAME
   21 
   22 WeBWorK::DB::Driver::SQL - SQL style interface to SQL databases.
   23 
   24 =cut
   25 
   26 use strict;
   27 use warnings;
   28 use DBI;
   29 
   30 use constant STYLE => "dbi";
   31 
   32 =head1 SOURCE FORMAT
   33 
   34 The C<source> entry for tables handled by this driver should consist of a DBI
   35 data source.
   36 
   37 =head1 SUPPORTED PARAMS
   38 
   39 This driver pays attention to the following items in the C<params> entry.
   40 
   41 =over
   42 
   43 =item usernameRO, passwordRO
   44 
   45 Username and password for read-only access to SQL database.
   46 
   47 =item usernameRW, passwordRW
   48 
   49 Username and password for read-write access to SQL database.
   50 
   51 =back
   52 
   53 =cut
   54 
   55 ################################################################################
   56 # constructor
   57 ################################################################################
   58 
   59 sub new($$$) {
   60   my ($proto, $source, $params) = @_;
   61 
   62   my $handleRO = DBI->connect_cached($source, $params->{usernameRO}, $params->{passwordRO});
   63   return 0 unless defined $handleRO;
   64 
   65   my $handleRW = DBI->connect_cached($source, $params->{usernameRW}, $params->{passwordRW});
   66   return 0 unless defined $handleRW;
   67 
   68   my $self = $proto->SUPER::new($source, $params);
   69 
   70   # add DBI-specific data
   71   $self->{handle}   = undef;
   72   $self->{handleRO} = $handleRO;
   73   $self->{handleRW} = $handleRW;
   74 
   75   return $self;
   76 }
   77 
   78 ################################################################################
   79 # common methods
   80 ################################################################################
   81 
   82 sub connect($$) {
   83   my ($self, $mode) = @_;
   84 
   85   if ($mode eq "ro") {
   86     $self->{handle} = $self->{handleRO};
   87   } else {
   88     $self->{handle} = $self->{handleRW};
   89   }
   90 
   91   return 1;
   92 }
   93 
   94 sub disconnect($) {
   95   my $self = shift;
   96 
   97   undef $self->{handle};
   98 
   99   return 1;
  100 }
  101 
  102 ################################################################################
  103 # dbi-style methods
  104 ################################################################################
  105 
  106 sub dbi($) {
  107   my ($self) = @_;
  108   return $self->{handle};
  109 }
  110 
  111 1;